Signal system



A. S. 'MMZEUIR? UL L11: L11? SIGNAL SYSTEM Filed Aug. 17, 1926 hpplicatlon filed duct W, 119th. aerial lilo. 1129359.

The present invention relates to tire alarm systems and more particularly to automatic systems adapted to associated'with the al telephone circuits tor giving an alarm upon occurrence of fire.

The object of the present invention is to provide a fire alarm system to be associated with a telephone system without alteration oit eting telephone circuits or interference with normal use of the instrument, and arranged automatically to transmit a signal over the telephone'lines upon excessive generation of heat in the vicinity of a predetermined point or points within a building.

With this obyect in view, the principal teatures oil the invention contemplates the provision ot means external to the telephone in a cut adaptedto close the telephone circuit to meet the instrument to the line independently of the usual hook controlled switch. This external means is associated with one or more heat responsive devices which act upon occurrence of an abnormal rise in temperature to aldord connection of the instent to the usual telephone lines.

fiimultaneously a signal device which is,

adapted to give an audible signal at the cen tral switch board is set into operation and continues til the apparatus is reset. lln

till

the simplest and most ecient form oi? the invention yet devised the external circuit closing means consists of a three element switch siumilar to the hook controlled switch and which is normally maintained in ,open position until closed by operation of a heat responsive device. The external switch neither'interleres with or is aflected by normal use of the telephone instrument for purposes ot conversation;

Uther leatures oi the invention consist in V certain novel features oi? construction, comlll tll

llli

binations and arrangements of parts hereinatter described and particularly defined in the claims.

lha the accompanying drawings, Fig. l is a circuit diagram of a fire alarm apparatus embodying the features of the present invention; Fig. 2 is a detail view of the circuit closing switch and signal control means; Fig. 3 is a section on line 3-8 of Fig. 2; and Fig. d is a view similar to Fig. 3 showing the switch in closed position.

Tn the illustrated embodiment of the present invention a three element switch similar to the hook controlled switch oil the telephone instrument is arranged externally oi the instrument and is adapted to have its separate elements connected to corresponding ele- The ' open position by a cam which upon operation through the intervention of the heat responsive devices serves to release the external switch to close the telephone circuit and to connect the instrument to the line-in a manner similar to the connection when the hook controlled switch is operated by removal of the receiver. The operation of one oil the heat responsive devices also closes an audible signal circuit which includes a buzzer associated with the telephone instrument, the buzzer being operated either continuously or intermittently according to a predetermined code by means ot a switch actuated by the release cam.

Reterring to the drawings, a telephone intill) strument indicated generally at Bis connected by a cord 8 with the usual box 10. A cord 12 connects with the receiver of the instrument which serves to hold depressed the hook 1t, thus maintaining the three element switch 16 ot the instrument in normally open position. The usual connections from the switch to the transmitter and receiver of the instrument hre not shown in the, drawings in order to avoid complications in detail. The fire alarm apparatus consists of a three element switch 18 having two short contact members 20 and a relatively long contact member 22, the construction of the switch being similar to that oil the switch 16. llorresponding elements of the switches are electrically coected together by wires 24 which connect to a suitable terminal block 28 arranged in any convenient location. The switch is maintained in open position by a release arm 30 which has a split pin 32 engaging with the long contact arm 22 and which is pivoted at one end upon a support 34. The release .arm is normally urged in a direction to close theswitch by a torsion spring 36 which is maintained in depressed position'by a cam 38. The release arm bears against the under side 0 the cam 38 which has a shoulder portion l0 arranged to permit a closing movement of the release arm upon rotation of the cam in the direction of the arrow. llpon occurrence oi? fire, a motor 42 which is connected by a shaft it and any suitable reducing gearing with the cam 38 is operated by one or more oil a plurality oi. alarm initiating devices, indicated as thermostats it which are arranged in parallel til till

ltlll ltlti llltl lines 48. The

with'each other and in series with an electrical source of supply indicated by the supply thermostats may be of the usual bimetallic construction arranged to flex and close an electrical contact upon generation of sufiicient heat thereby closing the motor circuit and operating to rotate the cam 38. The rotation of the cam permits rising of the release. 30 to the position shown in Fig. i which is entirely above the cam and the release bar is, therefore, thereafter unaffected by the rotation of the cam, thereby maintaining the telephone circuit closed until the apparatus is reset. e

The rotation of the cam 38 is also utilized to operate an audible signal device which is associated with the telephone instrument. The signal device consists of a buzzer 50 placed within the base of the instrument and connected by wires 52 through the terminal block 28 to oppositesides of the motor in order that the buzzer circuit may be energized simultaneously with the starting of the motor. The buzzer circuit includes a two contact switch 54 which is closed intermittently by the camwheel 38. To this end the cam is formed with a projection 56 which engages intermittently with a spring pressed plunger 58 hearing against one of the contacts and mounted in a suitable support 60. The cam may be formed with-one or more projections of any desired length in order that a suitable code signal may be generated in such a manner that the operator may properly distinguish the location of the instrument if the latter is on a party line.

Under normal conditions the switch 18 is maintained open and has no effect upon the operation of the telephone circuit. Upon occurrence of fire which results in closing of one or more of the thermostats the motor circuit is closed, thus rotating the cam in the direction of the arrow and closing the switch 18. This rotation of the cam also operates the buzzer circuit. The buzzer'by its position in the base of the instrument serves to vibrate the carbon granules of the transmitter as effectively as if it were placed directly in front of the instrument. Upon responding to the call set up by the closing of the switch 18 the operator hears the generated code signal transmitted by virtue of the operation of the buzzer 50. The rotation of the cam continues until all of the thermostats resume normal open position. After the alarm is answered, the switch 18 may be manually reset by depressing the release arm 30 and permitting theFcam wheel to rotate to the position shown in 1g. 2.

In practice, the thermostats 46 will be located 1n the parts of'the building which will be most susceptible to excessive generation of heat in order that operation of the system may be initiated immediately upon the occurrence of a fire. In the actual construction of the apparatus the wires 24 and 52 leadin from the telephone instrument to the terminal block 28 will be bundled in a single cord passing through an opening in the base of the instrument. The block 28, as well as other parts of the fire alarm apparatus, may be located in any convenient position, but in order to avoid a multiplicity of cords leading from the telephone it may be desirable to place the terminal block 28 within the box 10 in which case the wires 24 and 52, as well as those ordinarily included in the cord 8, may be bundled together in a single cord of larger diameter. In this latter construction, the wires leading from the terminal block to the external circuit closing switch 18 and the buzzer control switch 54=will lead directly from the box where they willin no wa interfere or become entangled with the tel ephone instrument.

It will be seen that normal use of the instrument for conversation purposes and the operation of the alarm are practically inde pendent of each other. The alarm system is always maintained in readiness for operation, and requires no settling or adjustment after its installation. Moreover, the alarm, when once initiated upon occurrence of a fire, operates until either the circuit is rendered inoperative by the fire or the switch is manually reset, thus assuring that the signal can not escape the attention of the central operator.

Having claimed is 1. An alarm apparatus comprising alarm initiating means, a normally stationary code wheel, means acting upon operation of the alarm initiating means for continuously rotating the code wheel, a signal circuit, a switch operated by the code wheel for intermittently opening and closing the signal circuit, a multiple element switch adapted to have its separate elements connected to the corresponding elements of the hook switch of a telephone instrument, a release cooperating with the multiple element switch and normally engaging t e code wheel to maintain the elements of the switch out of con tact with each other and constructed and arranged to be released and to permit permanent engagement of the contacts after starting of rotation of the code wheel.

2. An alarm apparatus comprising alarm initiating means, a motor, connections between the motor and the alarm initiating means to rotate the motor upon actuation of described the invention, whatis the alarm initiating means, a code wheel connected with the motor, a signal circuit, a switch in the signal circuit constructed and arrangedto be operated b the code wheel to intermittently open an close the signal circuit, a multiple element switch adapted to have its separate elements connected with the corresponding elements of the hook switch et tit telephehe instrument, at releeee arm her- L melly holding the elements ell the ewiteh eut et eenteet with each other end. having ehe enel engaging e uteee of the code Wheel, the eedle Wheel having e sheuleler egeihst which 7 closing et the multiple element swlteh when the sheultlere the eedle Wheel peeses the endl ml the teleeee mm on stettlnget t'etetieh W ef the eeele Wheel,

llh teetimehy Whereet ll heve sighed my name te this epeeifieetien.

DEE S. l 

